1. Field of the Invention
The present invention relates to a blend of a vinyl chloride polymer and an impact modifier which gives an improved impact resistance as compared to the vinyl chloride polymer alone. The impact modifier also functions as a heat distortion temperature improver and process aid for the vinyl chloride polymer.
2. Description of the Prior Art
The use of three-stage acrylic elastomer impact modifiers in blends containing a vinyl chloride polyer is known and is described in U.S. Pat. No. 3,655,826 to R. P. Fellmann et al. In this prior art patent a crosslinked (meth)acrylate/crosslinked styrene/uncrosslinked methacrylate or acrylate composition is described, and this additive is said to function as an impact modifier when admixed with the vinyl chloride polymer (Col. 5, lines 49-52 and 65-70).